A free-weight exercising barbell typically is a weighted form, shaped and sized to allow the exerciser to grip it securely, and to lift it and move it around during exercising. Free-weight barbells, during exercising, are solely supported by the exerciser and not by any structural means in the form of frame guides, cables or the like, as is common on stationary exercise machines.
A typical free-weight exercising barbell may consist of a pair of substantially equal weights spaced apart near the opposite ends of a gripping handle or bar, which may be long enough to allow it to be gripped between the weights by only one hand or by both hands. The center of gravity of the barbell generally is located somewhere along the axis of the gripping bar, typically at the mid-point of a barbell, symmetrically of the one-hand grip or between the two-hand grip.
During a typical exercise, an exerciser may lift the barbell between lower and upper positions, once or repetitively, whereupon specific muscles will be stressed to varying degrees of maximum. Exercises may be done: (1) with both hands gripping and moving a single barbell, to move in unison and cooperatively together; (2) with only a single hand gripping and moving a single barbell, while the other hand would be free and not involved in the exercise; or (3) with each hand gripping and moving a separate barbell, independently and not necessarily in unison or cooperatively.
The movement of the gripping hand(s) generally will be along a path having a large vertical component, perhaps even straight up-and-down; may be arcuately with both horizontal and vertical components; or could even be only horizontally.
Unless otherwise referring to a specific barbell of this disclosure, for simplicity sake, the general discussion that follows will be directed to a single-hand barbell.
One common exercise done with a free-weight barbell is the "curl", which the exerciser may do when standing or sitting with the upper body torso generally aligned vertically, or while lying against an inclined board whereupon the upper body torso and upper arm between the shoulder and elbow are angled the same as the incline of the board. During the curl, the upper arm preferably will be kept generally aligned with and at the side of the upper body torso. In the lower position, the arm is substantially straight, so that the lower arm between the elbow and gripping hand is also generally aligned with and at the side of the exerciser and the gripping hand is vertically lower than the elbow. The exerciser lifts the barbell from this lower position, by bending the arm only at the elbow, while the upper arm generally remains aligned at the exerciser's side, until in the upper position, the lower arm is angled upwardly away from the elbow and the gripping hand is vertically higher than the elbow, in front of and spaced from the upper body torso but reasonably close to the shoulder.
During the exercise, the gripping hand may move along an arcuate path around the elbow; and this arcuate path typically will define a plane extended through the elbow, the shoulder, or both, and may also be approximately vertically. The bicep muscle is stressed during this exercise, being evident by its bulge particularly when the gripping bar is aligned somewhat along a horizontal axis and the exerciser's palm faces upwardly.
The inventor has noticed that the efforts needed for the stressed bicep muscle to move and/or hold the barbell at various locations between the lower and upper positions vary substantially, particularly toward the upper position when the upper arm begins to be angle upwardly from the elbow. Thus, substantially less bicep effort is needed to hold the barbell near or in the upper position; and in fact, if poor form or the like aligns the gripping hand and barbell vertically above the elbow, the bicep may be allowed to become almost totally unstressed, almost as a rest period.
As the exercised muscles develop in size and/or strength and/or endurance, depending on the degree and/or duration of stressing, any rest period may detract from the effectiveness of the exercise. Also, certain portions of the bicep muscle, such as the top close to the shoulder, are not stressed significantly during a typical standing curl.
Other exercises commonly performed with free-weight barbells frequently have the same characteristic, vis, the muscle(s) primarily stressed to lift the barbell between the lower and upper positions, in fact, is(are) allowed to become somewhat or possibly even totally unstressed in the upper position.
One example is the "chest fly", performed with the exerciser lying on his/her back on a horizontal or inclined bench, which involves lifting a pair of barbells, one in each hand, from lower positions where the arms are extended substantially horizontally away from the body torso, to upper positions where the arms are extended substantially vertically from the body torso. With the arms held substantially straight, each gripping hand may move along a substantially vertical plane extended approximately through the shoulder. The chest muscles are stressed during this exercise; however, in the upper position, with the gripping hands and barbells aligned vertically over the shoulders, the chest muscles are allowed to become almost completely relaxed.
Another example is the "press", performed with the exerciser standing or sitting with the upper body torso aligned vertically or lying on his/her back on a horizontal or inclined bench, which involves lifting a barbell from a lower position where the arms are bent at the elbows and the barbell is at or close to the shoulders, to an upper position where the arms are extended substantially straight and the barbell is vertically aligned above the shoulders. The tricep muscle is stressed to move the barbell between these positions; but in the upper position, this muscle is allowed to become almost completely relaxed.